Quick, digital-only thoughts from In the Wake of the News columnist David Haugh.

After three weeks of training camp in Bourbonnais, the Bears will leave Wednesday morning after a final walk-through. What are the 10 things you could say on the last day of practice that you couldn’t say on the first? Thanks for asking:

1. Depth and stability on the offensive line went from a strength to a concern.

At the beginning of camp, the O-line represented the deepest position group. Then starting guard Kyle Long missed time with a virus and an ankle problem. And starting right tackle Jordan Mills showed up Sunday in a walking boot because the left foot he broke in Week 17 last season still hurt. Quality backup Brian De La Puente injured his knee and another, Eben Britton, tweaked his hamstring. Suddenly, the unit that started the same five guys for 16 games in 2013 faced uncertainty it never encountered a year ago. Every team deals with injuries. The Bears must overcome them for their offense to function as well as expected.

2. Jimmy Clausen showed he was a quick learner and the best available backup quarterback on the roster.

Clausen grasped the offense quickly and threw the ball with more authority and accuracy than Jordan Palmer, who has been overvalued by the Bears since Josh McCown left town. Nobody’s saying Clausen could run the Bears offense as well as McCown did in Cutler’s absence, but early indications are he has rebounded from shoulder surgery well enough to reboot his NFL career in Chicago. If Kyle Orton makes the unlikely decision to come out of retirement, the Bears still should call but, if not, Clausen looks like a capable alternative – or at least more capable than Palmer. That’s why he will be the No. 2 quarterback Thursday.

3. The new defensive front appears active and edgy.

Lamarr Houston stood out consistently, and even mixed it up occasionally. Willie Young showed a burst. Jeremiah Ratliff has yet to look 32. Stephen Paea enjoyed a solid start he needed. And we have yet to see much from Jared Allen, who missed the first exhibition game due to family reasons. General manager Phil Emery so far likes the results of the defensive line he revamped via free-agency.

4. The returning young linebackers still look too young.

Shea McClellin encountered an old problem at his new position of strong-side linebacker; he struggled at the point of attack stopping the run. Same goes for Jon Bostic against the pass, where he lacks awareness. For the Bears defense to improve, it needs one or both those young linebackers to elevate their play because Lance Briggs and D.J. Williams, at their ages, can’t be considered locks to start 16 games.

5. The Bears suddenly have a roster battle at tight end.

Martellus Bennett remains entrenched as a starter, even after missing an exhibition due to a suspension that likely will be forgotten quickly. In his absence, Zach Miller emerged as the offensive surprise of camp and Dante Rosario performed well, too. When you consider the Bears signed Matthew Mulligan in free-agency to be the backup blocking tight end, you start to wonder if the roster has room for four tight ends. All potentially serve a purpose, but that’s a luxury the Bears might not be able to afford.

Not once has Conte hinted his bum shoulder had anything to do with a bad season in 2013. Maybe it didn’t, but good for him in avoiding saying anything that sounded like an excuse. Instead, Conte came out edgier than ever, acknowledging how critics on a list he has motivate him to have a bounce-back year. The Bears have good competition at safety and the confident return of Conte – whose 40 NFL starts can’t be ignored – puts him squarely in the mix.

7. First-round draft pick Kyle Fuller looks the part.

Believe it or not, Fuller did something more meaningful in Bourbonnais than get body-slammed by Bennett. He assimilated seamlessly into the Bears defense as the third cornerback, forcing Tim Jennings inside to play nickel on many passing downs. Fuller plays physical and without hesitation, two traits valued in any defensive back.

After Marquess Wilson went down, the Bears tried some other options at the No. 3 receiver role. Eric Weems, Josh Morgan, et al. Truth is, the most qualified replacement for Wilson is currently on another roster. After the first round of cuts, the Bears will have a deeper pool of possibilities they might like more than veteran discards such as Santonio Holmes, who they put through a workout.

9. Tackling has been emphasized.

It only will matter if the Bears defense continues to show such improvement bringing down ballcarriers when the games count. But besides bad personnel, bad tackling had as much to do with the downfall of the 2013 defense as anything – a fact the Bears clearly have committed to changing.

10. The special teams are the opposite of special – so far.

It was the first exhibition game for a team with so many new faces. Lapses in coverage and execution are expected. That’s not making an excuse as much as stating reality. Questions remain at punter and long-snapper. No area shows more growth over the course of preseason than special teams, so be careful not to overreact after one game. They need time.

BOURBONNAIS -- Jimmy Clausen is scheduled to be the first backup quarterback off the bench behind starter Jay Cutler when the Chicago Bears host the Jacksonville Jaguars in an exhibition Thursday night, coach Marc Trestman said Tuesday.

Chicago Tribune sports columnist Steve Rosenbloom takes a closer look at the Bears' special teams unit. While it may be difficult to fill the shoes of former kick returner Devin Hester, the unit can only get better.